1. Field of the Invention
The present invention relates to a motion compensation device which compensates for blur in an image in optical systems, instruments and the like. In particular, the present invention relates to a motion compensation device with an improved clamp structure for the motion compensation optical system.
2. Description of the Related Art
Image blur suppression devices have as their object, suppression of, or reduction of, blurring in an image projected onto an image plane. A motion compensation device is a type of image blur suppression device which compensates for motion incident upon an optical system which projects the image onto the image plane. Motion is typically imparted to the optical system by way of vibrations in the optical system, or in the surrounding holding member. In general, known motion compensation devices cause a compensation lens to shift counter to the motion of the optical system so as to shift the image projected by the optical system relative to the optical system.
Heretofore, in this kind of motion compensation device, for example, it is known to provide a locking mechanism wherein a conical depression is disposed in the lens holding frame which holds the compensation lens. By linearly moving a conical convex member in a direction parallel to the optical axis and by tightly pressing the conical convex member into the conical depression so as to engage in a state where the center lines of the concave and convex cones coincide, it is possible to control the movement in two mutually perpendicular directions, which are at right angles to the optical axis of the lens holding frame. Further, the compensation lens is now in a locked state. Such a structure for this motion compensation device is disclosed in Japanese Laid Open Patent Publication 6-67274.
However, because engagement was caused by the roughness of the cones in the optical axis direction, in the case of commencing motion compensation, in order to drive the motion compensation optical system to release this engagement, a time lag arose in the prior art motion compensation device.
Moreover, when not performing motion compensation, because the concave and convex portions of the cones lock due to movement in the optical axis direction, in the case that the compensation lens is not in a predetermined position, e.g., centered, a reliable lock was not possible.